<?php

namespace App\Http\Controllers\Api;

use App\Http\Controllers\Controller;
use Illuminate\Http\JsonResponse;
use Laravel\Horizon\Contracts\JobRepository;
use Laravel\Horizon\Contracts\MetricsRepository;
use Laravel\Horizon\Contracts\WorkloadRepository;
use Laravel\Horizon\Jobs\RetryFailedJob;

class QueueMonitorController extends Controller
{
    public function __construct(
        private readonly JobRepository      $jobs,
        private readonly MetricsRepository  $metrics,
        private readonly WorkloadRepository $workload,
    ) {}

    /**
     * GET /api/queue/jobs/recent
     * Recent processed jobs tracked by Horizon.
     */
    public function recent(): JsonResponse
    {
        $jobs = $this->jobs->getRecent();

        return response()->json([
            'success' => true,
            'total'   => $this->jobs->countRecent(),
            'data'    => $this->formatJobs($jobs, 'completed'),
        ]);
    }

    /**
     * GET /api/queue/jobs/pending
     * Jobs currently waiting in the queue (per-queue workload + Horizon pending list).
     */
    public function pending(): JsonResponse
    {
        $jobs     = $this->jobs->getPending();
        $queues   = $this->workload->get();

        $workload = collect($queues)->map(fn (array $q) => [
            'queue'     => $q['name'],
            'length'    => $q['length'],
            'wait'      => $q['wait'],
            'processes' => $q['processes'],
        ])->values();

        return response()->json([
            'success'  => true,
            'total'    => $this->jobs->countPending(),
            'workload' => $workload,
            'data'     => $this->formatJobs($jobs, 'pending'),
        ]);
    }

    /**
     * GET /api/queue/jobs/failed
     * Failed jobs tracked by Horizon.
     */
    public function failed(): JsonResponse
    {
        $jobs = $this->jobs->getFailed();

        return response()->json([
            'success' => true,
            'total'   => $this->jobs->countFailed(),
            'data'    => $this->formatJobs($jobs, 'failed'),
        ]);
    }

    /**
     * POST /api/queue/jobs/failed/{id}/retry
     * Re-queue a failed job by its Horizon job ID.
     */
    public function retry(string $id): JsonResponse
    {
        abort_if(!$this->jobs->findFailed($id), 404, "Can't find failed job #{$id}");

        dispatch(new RetryFailedJob($id));

        return response()->json(['success' => true, 'message' => 'Job đã được đưa lại vào hàng đợi']);
    }

    /**
     * GET /api/queue/jobs/metrics
     * Queue throughput, runtime, and per-queue/per-job breakdown.
     */
    public function metrics(): JsonResponse
    {
        $measuredQueues = $this->metrics->measuredQueues();
        $measuredJobs   = $this->metrics->measuredJobs();

        $queueMetrics = collect($measuredQueues)->map(fn (string $queue) => [
            'queue'      => $queue,
            'throughput' => $this->metrics->throughputForQueue($queue),
            'runtime_ms' => round($this->metrics->runtimeForQueue($queue), 2),
        ])->values();

        $jobMetrics = collect($measuredJobs)->map(fn (string $job) => [
            'job'        => $job,
            'throughput' => $this->metrics->throughputForJob($job),
            'runtime_ms' => round($this->metrics->runtimeForJob($job), 2),
        ])->values();

        return response()->json([
            'success' => true,
            'data'    => [
                'throughput'               => $this->metrics->throughput(),
                'jobs_processed_per_minute' => $this->metrics->jobsProcessedPerMinute(),
                'counts'                   => [
                    'recent'           => $this->jobs->countRecent(),
                    'pending'          => $this->jobs->countPending(),
                    'failed'           => $this->jobs->countFailed(),
                    'completed'        => $this->jobs->countCompleted(),
                    'recently_failed'  => $this->jobs->countRecentlyFailed(),
                ],
                'queues' => $queueMetrics,
                'jobs'   => $jobMetrics,
            ],
        ]);
    }

    /**
     * Normalize a collection of Horizon job objects into a consistent array shape.
     *
     * @param  \Illuminate\Support\Collection  $jobs
     * @param  string  $defaultStatus
     * @return \Illuminate\Support\Collection
     */
    private function formatJobs(\Illuminate\Support\Collection $jobs, string $defaultStatus): \Illuminate\Support\Collection
    {
        return $jobs->map(function (object $job) use ($defaultStatus) {
            $payload = isset($job->payload) ? json_decode($job->payload, true) : [];

            return [
                'id'           => $job->id ?? null,
                'name'         => $payload['displayName'] ?? $job->name ?? null,
                'queue'        => $job->queue ?? null,
                'status'       => $job->status ?? $defaultStatus,
                'attempts'     => $job->attempts ?? 0,
                'started_at'   => $this->formatTimestamp($job->reserved_at ?? null),
                'completed_at' => $this->formatTimestamp($job->completed_at ?? null),
                'failed_at'    => $this->formatTimestamp($job->failed_at ?? null),
                'exception'    => $job->exception ?? null,
            ];
        })->values();
    }

    /**
     * Convert a Unix timestamp to ISO-8601 string, or return null.
     */
    private function formatTimestamp(int|float|string|null $ts): ?string
    {
        if ($ts === null || $ts === 0) {
            return null;
        }

        return \Carbon\Carbon::createFromTimestamp((int) $ts)->toIso8601String();
    }
}